Lay the grouper on a flat surface and remove any little bones with tweezers.
Going with the grain, carefully cut the fish on the diagonal into 4 smaller fillets.
Place the buttermilk in a shallow dish.
Combine the flour, paprika, salt and pepper in a second shallow dish. Dip the
fillets into the buttermilk and then dredge in the seasoned flour, shaking off excess.
Heat butter and oil in a large, nonstick skillet over medium heat. Cook fillets
one or two at a time, depending on size of the skillet, until golden brown and cooked
through, about 3 minutes per side. Add more butter and oil to the pan if necessary.
While the fish is cooking, spread both sides of each bun with 1 tablespoon tartar
sauce. Place a grouper fillet on the bottom half of each bun, top with lettuce and
tomato, if desired, and cover with the top of the bun.
* If grouper is not available, use snapper or sea bass.